Polish mathematician

1. Stefan Banach
Group 3

2. Who was Stefan
Banach?
He was a Polish mathematician who is generally
considered one of the 20th century's most important
and influential mathematicians. He was the founder of
modern functional analysis, and an original member of
the Lwów School of Mathematics.
His major work was the 1932 book, Théorie des
opérations linéaires (Theory of Linear Operations), the
first monograph on the general theory of functional
analysis.

3. Stefan Banach's
achievements
He authored over 50 scientific papers,
including Theory of Linear Operations.
Other notable mathematical concepts that
bear Banach's name include Banach
spaces, Banach algebras, Banach measures,
the Banach–Tarski paradox, the Hahn–
Banach theorem, the Banach–Steinhaus
theorem, the Banach–Mazur game,
the Banach–Alaoglu theorem, and
the Banach fixed-point theorem.

4. General information about Stefan
Banach
He was born March 30, 1892 in Kraków, died August 31,
1945 in Lviv. tefan Banach was born on 30 March 1892 at St. Lazarus General
Hospital in Kraków, then part of the Austro-Hungarian Empire, into a Góral Roman
Catholic family, and was subsequently baptised by his father. Banach's parents were
Stefan Greczek and Katarzyna Banach, both natives of the Podhale region. Greczek was
a soldier in the Austro-Hungarian Army stationed in Kraków. Little is known about
Banach's mother. According to his baptismal certificate, she was born in Borówna and
worked as a domestic helper.

5. Otto Nikodym and
Stefan Banach
Memorial Bench
in Kraków, Poland
(sculpted by Stefan
Dousa)

6. Early life and education
• In 1902, Banach, aged 10, enrolled in Kraków's IV Gymnasium (also known as the Goetz Gymnasium).
While the school specialized in the humanities, Banach and his best friend Witold Wiłkosz (also a
future mathematician) spent most of their time working on mathematics problems during breaks and
after school. While Banach was a diligent student he did, on occasion, receive low grades (he failed
Greek during his first semester at the school) and later spoke critically of the school's math teachers.
• After obtaining his matura (high school degree) at age 18 in 1910, Banach moved to Lwów (today
called Lviv) with the intention of studying at the Lwów Polytechnic. He initially chose engineering as
his field of study since at the time he was convinced that there was nothing new to discover in
mathematics.
• When World War I broke out, Banach was excused from military service due to his left-handedness
and poor vision. He made his living as a tutor at the local schools, worked in a bookstore and as a
foreman of a road building crew. He attended some lectures at the Jagiellonian University at that
time, including those of the famous Polish mathematicians Stanisław Zaremba and Kazimierz
Żorawski, but little is known of that period of his life

7. See the Youtube video – just copy and
paste the link in the browser:
https://youtu.be/ZUHWNfqzPJ8

8. Banach meets Hugo Steinhaus
In 1916, in Kraków's Planty park, Banach encountered Professor Hugo Steinhaus, one of the
renowned mathematicians of the time. According to Steinhaus, while he was strolling
through the gardens he was surprised to overhear the term "Lebesgue integral" (and walked
over to investigate. As a result, he met Banach, as well as Otto Nikodym. Steinhaus became
fascinated with the self-taught young mathematician. The encounter resulted in a long-
lasting collaboration and friendship. In fact, soon after the encounter Steinhaus invited
Banach to solve some problems he had been working on but which had proven difficult.
Banach solved them within a week and the two soon published their first joint work (On the
Mean Convergence of Fourier Series).

9. Steinhaus, Banach and Nikodym, along with several other Kraków mathematicians (Władysław
Ślebodziński, Leon Chwistek, Alfred Rosenblatt and Włodzimierz Stożek) also established a mathematical
society, which eventually became the Polish Mathematical Society. The society was officially founded on 2
April 1919. It was also through Steinhaus that Banach met his future wife, Łucja Braus.
Scottish Café, meeting place of many famous
Lwów mathematicians

10. Private life
In 1920 he
married
Łucja Braus.

11. Recognition
•In 1946, the Stefan Banach Prize was established by the Polish Mathematical Society.
•In 1992, the Institute of Mathematics of the Polish Academy of Sciences established a special Stefan Banach Medal for
outstanding achievements in mathematical sciences
•Stefan Banach is the patron of a number of schools and streets including
in Warsaw, Lviv, Świdnica, Toruń and Jarosław.
•In 2001, a minor planet 16856 Banach, discovered by Paul Comba in 1997, was named after him.
•In 2012, the National Bank of Poland celebrated the mathematician's achievements by issuing a series of
commemorative coins designed by Robert Kotowicz.
•In 2016, a commemorative bench featuring Banach and Otto Nikodym was unveiled in Kraków's Planty Park on the 100th
anniversary of the conversation the two mathematicians held when they first met Hugo Steinhaus, which proved
instrumental in the development of his scientific career.
•In 2021, one of the episodes of Polish documentary TV series Geniusze i marzyciele (Geniuses and Dreamers) aired
on TVP1 and TVP Dokument channels was devoted to Stefan Banach.
•In 2022, Google Doodle commemorated the 100th anniversary of Banach receiving his title of professor.

12. The end.
Thank you for you attention.